I am very sorry to hear of the ordeal you have been through. I completely understand that you do not want to disappoint your children and have planned for this trip for so long. BUT, I am going to suggest that you reschedule the trip for so many reasons....first off your physical and emotional health. You need to recover from the bruising. I am not sure how walking miles in the park is going to feel in the condition you are in. I know bruises can hurt for days after. Second, your heart is just not in it now as much as you want it to be, please ask yourself if you will be thinking of what just happened or if you can truly focus on enjoying time spent with your children with things so unresolved back home.
I understand the love of Disney as much as many people on this board, I moved to California partly because I love
Disneyland so much. I have also went on a vacation to Disney when I was dealing some painful situations in my life (not the same as what you are going through, but painful, nonetheless) and I honestly think I would have been better postponing my trip. Forgive me if I have missed whether you can reschedule or not...
I did not recall reading anything about your financial situation at this time, other than you could not afford the hotel so you came back home. I am not asking you to divulge this information, but were you getting help from him to pay the rent/bills, if spending the money on the trip is wise at this time.
Just wanting you to consider all of the aspects of going on a trip at this time. Whatever you decide, I wish you the best...don't ever let him back into your life, it becomes a pattern and if you think it was bad this time, next time it could be worse. You and your children deserve better, remember that.